Poisons
Household plants and foods that your pets should avoid.

Pet First Aid Ready Reference
Plants can be dangerous for our pets, even ones that are good for us…  Some can become life threatening very quickly!  They can cause anxiety, diarrhea, vomiting, abdominal pain, or make them feel so ill they don’t want to eat.  They can also cause damage to their hearts, kidneys, brains, livers, or blood cells. If you are concerned that your pet has gotten into any of these plants, please contact your local veterinarian or emergency clinic as soon as possible!

 
These plants include, but are not limited to…
Avocado – birds are very sensitive
Azaleas and Rhododendrons
Oleander
Yew
Tobacco
Cannabis (Marijuana, Pot, Weed…)
Chocolate (Cacao) – The darker the chocolate the more dangerous, and the more they eat per pound of pet the more toxic it becomes
Sago Palm
Grapes and Raisins
Lilies – especially cats
Plants that contain “soluble oxalates” like rhubarb, star fruit, beets, and shamrock plants
Plants that contain “insoluble oxalates” like Elephant’s Ear, Philodendron, Dieffenbachia, Dumb Cane, Peace Lily, Calla Lilly, Caladium, Jack-in-the-Pulpit, and Arrowhead plant
Hops
Onions, leeks, garlic, chives
Blue-green algae
Amanita mushrooms
 
Sometimes the toxic elements of these plants are used by use as medications or drugs.  For example, Tobacco contains the toxin nicotine, which is also found in cigarettes, gums, chews, or snuff.  Another example is the caffeine found in chocolate (not the only, or worst toxin in chocolate) that is also in coffee, teas, sodas, and pills.
 
Sometimes these poisonous plants act very fast, but others take days or more before your pet starts showing signs of feeling unwell.
 
Here are some links for more information:
http://www.petpoisonhelpline.com/pet-owners/
http://www.ansci.cornell.edu/plants/dogs/